The invention concerns a fuel to operate Diesel engines, in particular in cars, wherein the fuel contains an antioxidant.
Diesel fuels for cars are obtainable at many service stations. Modern Diesel fuels contain a number of additives, inter alia also antioxidant agents, which ensure, for example, the storing and ageing stability of the fuel.
In recent years, new Diesel fuel formulations are available in many markets which fuels are intended to reduce certain undesirable emissions and other undesirable characteristics. For example, since June 2004 new Diesel fuels are available on the German market, that are offered in addition to the conventional Diesel fuels. These new fuels are characterized by great improvement of the output, reductions of the noxious materials in the exhaust gas and decrease of consumption. Apart from the markedly reduced intensity of odor, a further feature of these fuels is its water white appearance. This crystal clear appearance should express, inter alia, the particular operational efficiency of the fuel. The color picture of the new Diesel fuel with approx. 50 Hazen markedly differs from the color reference numbers of conventional Diesel fuels, that have values of 200-300 Hazen.
A problem has occurred due to the fact, that the water white color of the new fuel during storage or when the fuel was exposed to daylight or sunshine, could not be maintained. Depending on the intensity of the incident light a discoloration of the fuel towards the yellowish occurred to a greater or lesser degree.